Use of Microorganisms as Nutritional and Functional Feedstuffs for Nursery Pigs and Broilers

The objectives of this review paper are to introduce the structures and composition of various microorganisms, to show some applications of single cells as alternative protein supplements or energy feeds in swine and poultry diets, and to discuss the functional effects of microorganisms as feed additives on the growth performance and intestinal health of nursery pigs and broilers. Microorganisms, including bacteria, yeasts, and microalgae, have been commonly supplemented in animal diets because they are cost-effective, stable, and have quantitative production that provides nutritional and functional benefits to pigs and broilers. Microorganisms could be alternative antibiotics to enhance intestinal health due to bioactive components from cell wall components, which interact with receptors on epithelial and immune cells. In addition, bioactive components could be digested by intestinal microbiota to produce short-chain fatty acids and enhance energy utilization. Otherwise, microorganisms such as single-cell protein (SCP) and single-cell oils (SCOs) are sustainable and economic choices to replace conventional protein supplements and energy feeds. Supplementing microorganisms as feedstuffs and feed additives improved the average daily gain by 1.83%, the daily feed intake by 0.24%, and the feed efficiency by 1.46% in pigs and broilers. Based on the properties of each microorganism, traditional protein supplements, energy feeds, and functional feed additives could be replaced by microorganisms, which have shown benefits to animal's growth and health. Therefore, specific microorganisms could be promising alternatives as nutritional and functional feedstuffs in animal diets.

Relationship between pork fatty acid content in selected muscles and carcass tissues

Pork plays a central role in culinary tradition in Central Europe. Most of the studies determine the fatty acid (FA) content separately in muscles and subcutaneous fat. However, it is also important to determine the FA content of meat products, which contain a mixture of muscles and fat. The determination of FA in carcass tissues is difficult and leads to the destruction of the whole carcass. Thus, the aim of this study was to estimate the FA content of carcass meat (muscles with inter- and intramuscular fat, MC), and carcass soft tissues (muscles with inter- and intramuscular fat and subcutaneous fat, SC) based on a single muscle. Fatty acids were analysed using gas chromatography. Thirty crossbred pigs were fed diets differing in their fatty acid content and n-6:n-3 polyunsaturated fatty acid (PUFA) ratio. Samples of Longissimus thoracis et lumborum (LL), Biceps femoris (BF), Semitendinosus (ST), and Semimembranosus (SM) muscles, MC, and SC were taken. Correlation between linolenic, eicosapentaenoic and docosahexaenoic acids contents and n-6:n-3 PUFA in examined muscles and MC ranged from 0.809 (SM) to 0.961 (LL), from 0.708 (LL) to 0.954 (ST), from 0.907 (SM) to 0.941 (ST), respectively (P = 0.000). Correlation between linolenic, eicosapentaenoic and docosahexaenoic acids contents and n-6:n-3 PUFA in examined muscles and SC ranged from 0.773 (SM) to 0.954 (LL), 0.763 (LL) to 0.983 (BF), and from 0.909 (LL) to 0.940 (ST), respectively (P = 0.000). Results allow estimate the FA content of MC and SC based on their content in single muscles.

Transcriptional response of porcine skeletal muscle to feeding a linseed-enriched diet to growing pigs

BACKGROUND

To investigate the effect of feeding a linseed-enriched diet to growing-finishing pigs on gene expression in skeletal muscle, pigs were fed with a linseed-enriched diet for 0, 30, 60 and 90 d. Transcriptional profiles of longissimus dorsi muscle were measured using Affymetrix Genechip.

RESULTS

Results showed that 264 genes were identified as differentially expressed genes (DEGs). The strongest transcriptional response was clearly observed at 30 d. DEGs were assigned to several main functional terms, including transcription, apoptosis, intracellular receptor-mediated signaling, muscle organ development, fatty acid metabolic process, cell motion, regulation of glucose metabolic process, spermatogenesis and regulation of myeloid cell differentiation. We also found that transcriptional changs of several transcription cofactors might contribute to n-3 PUFAs regulated gene expression. In addition, the increased expression of IGF-1, insulin signaling pathway and the metabolism of amino acids might involve in the muscle growth induced by feeding a linseed-enriched diet. The results also provide the new evidence that the expression changes of PTPN1, HK2 and PGC-1α might contribute to the regulation of insulin sensitivity by n-3 PUFAs.

CONCLUSIONS

Our finding provided correlative evidence that feeding the linseed enriched diet affact expression of genes involved in insulin signaling pathway and the metabolism of amino acids.